Electric-arc lamp.



No. 677,985. Patented July 9, I901.

D. HIGHAM.

ELECTRIC ARC LAMP.

(Application filed Apr. 22, 1901.)

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7 UNITED STATES PAT NT- OFFICE.

DANIEL HIGHAM, OF WINTHROP HIGHLANDS, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, OF NEW YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of LettersPatent- N 0.67798 5, dated July 9, 1901. Application filed April 22, 1901'. I Serial No' 56,822 (No model.)

To aZZ whom it may concern: 7

Be it known that I, DANIEL HIGHAM, a citizen of the United States, residing at Winthrop Highlands, county of Suffolk, State of Massachusetts, have invented certain new and useful Improvements in Electric -Arc Lamps, (Case No. 1,958,) of which the following is a specification.

My present invention comprises certain improvements designed to secure stability and steadiness of operation of electric-arc lamps.

In accordance with my invention I provide means responsive to movements of the arcregulating mechanism of the lamp for varying an external resistance or other currentcontrolling device in circuit with the lamp, these variations being. of such character as to check the variations of current in the lamp, to which they are either directly or indirectly due.

For a better understanding of my invention reference is to be had to the following description, taken in connection with'the accompanying drawing.

As to the scope of my invention, 1 do not wish to be limited to the particular construction of the same herein set forth, but desire that it shall be determined by reference to the particular statements of the same as set forth in the claims appended hereto.

The drawing, which represents one embodiment of myinvention, partly in diagram, sets forth a construction in which the pressure of fluid in the dash-pot of the lamp performs the double function of preventing too violent reciprocation of the movable parts of the lamp and at the same time by its variation of pressure acts through suitable mechanism to vary a resistance in circuit with the lamp.

Referring more in detail to the drawing, 1 and 2 indicate two solenoids suitably mounted on the frame of the lamp (not shown) and acting in the usual manner upon a U-shaped core 3. This core is attached to a tubular reciprocating carbon-carrier 4, which is provided'at its lower end 5 with a clutch 6 of any suitable construction for engaging the carbon or other electrode 7, the upper portion of which is concealed within the tubular carrier 4. The lower carbon is indicated at 8.

In circuit with the solenoids 1 2 and the carbons 7 8 is included some current-varying deviceas, for example, a rheostat 9, the resistance of which is adapted to be varied by variation of pressure. This device is of a character well known in the art, and may consist of a pile of carbon plates arranged one on top of the other and confined between conducting end plates 10 and 11. The end plates are urged together by means of the pressure exerted upon the plate 10 by means of the weighted lever 12, pivoted at 13 to some stationary part "of the lamp and at its other end connected through a link 14 to the central portion of an easily-flexible diaphragm 15, which serves to close the upper portion of a dash-pot 16, within which moves a piston 17 mechanically actuated by the feeding mechanism of the lamp, the piston in this case being shown as mounted directly upon the upper end of the carrier 4.

With the construction shown it will be seen that in the case of a sudden increase in the current through the lamp, due to closing its circuit or otherwise, the core 3 and the carrier 4 connected thereto will be given an upward movement, which thereby results in the compression of the air or other fluid in the chamber of the dash-pot 16. The resistance to compression of the fluid opposes the upward movement of the carrier 4, while the increase in pressure by bulging out the diaphragm 15 acts through the link 14 and the lever 12 to relieve to a greater or less extent the pressure on the current-varying device 9, thereby increasing the resistance in circuit with the lamp and so helping to reduce the current in the lamp to its normal value. Upon a sudden decrease in current, due to any cause, the reverse operation takes place, as will readily be understood.

While I have illustrated my invention in connection with so much of an arc-lamp as may be necessaryto an understandingthereof, it is to be understood that my invention is not to be confined to any particular type of arc-lamp, but is applicable to many different varieties. Among others, it is very beneficialin connection with lamps of the inclosed- -arc type, but is, however, not to be limited to use in connection therewith.

lVhat I claim as new, and desire to secure by Letters Patent of the United States, is 1. In an electric-arc lamp, the combination of feeding mechanism, a body of elastic fluid adapted to be compressed in response to movement of said feeding mechanism, and a current-varying device responsive to variations of pressure of said elastic fluid.

2. In an electric-arc lamp, the combination of feeding mechanism, a dash pot, a diaphragm adapted to be flexed by variation of pressure in said dash-pot, and a current-varying device operatively related to said diaphragm.

3. In an electric 1amp,.the combination of feeding mechanism, a variable resistance in circuit with the lamp, and an elastic connection between the feeding mechanism and the Variable resistance.

i. In an electric lamp, the combination of feeding mechanism, a dash-pot operatively 

